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Brincidofovir (Oral)

Medically reviewed by Last updated on Aug 3, 2022.

Oral route(Tablet;Suspension)

Warning: Increased Risk for Mortality When Used for Longer DurationAn increased incidence of mortality was seen in brincidofovir-treated subjects compared to placebo-treated subjects in a 24-week clinical trail when brincidofovir was evaluated in another disease .

Commonly used brand name(s)

In the U.S.

  • Tembexa

Uses for brincidofovir

Brincidofovir is used to treat human smallpox disease caused by the variola virus.

Brincidofovir is available only with your doctor's prescription.

Before using brincidofovir

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For brincidofovir, the following should be considered:


Tell your doctor if you have ever had any unusual or allergic reaction to brincidofovir or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Appropriate studies performed to date have not demonstrated pediatric-specific problems that would limit the usefulness of brincidofovir in the pediatric population.


Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of brincidofovir in the elderly.


There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

Interactions with food/tobacco/alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other medical problems

The presence of other medical problems may affect the use of brincidofovir. Make sure you tell your doctor if you have any other medical problems, especially:

  • Liver disease—Use with caution. May make this condition worse.
  • Weak immune system—Use with caution. May increase risk for serious side effects.

Proper use of brincidofovir

Take brincidofovir only as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.

Brincidofovir comes with a patient information leaflet. Read and follow the instructions carefully. Ask your doctor if you have any questions.

To use the tablet:

  • Swallow the tablet whole. Do not crush, divide, or break it.
  • You may take brincidofovir on an empty stomach or with a low-fat meal.

To use the oral liquid:

  • Shake the bottle well just before each use.
  • Measure the oral liquid medicine with a marked oral syringe.
  • It is best to take brincidofovir on an empty stomach.
  • If you cannot swallow the oral liquid, you may give it through a nasogastric or gastrostomy tube.

Do not touch the broken or crushed tablet or oral liquid. If you touch it, wash your hands with soap and water. If it got in your eyes, rinse your eyes with water.


The dose of brincidofovir will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of brincidofovir. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For smallpox:
    • For oral dosage form (tablets):
      • Adults and children weighing 48 kilograms (kg) or more—200 milligrams (mg) (two 100 mg tablets) once a week for 2 doses (on Days 1 and 8).
      • Children weighing less than 48 kg—Use of oral liquid is recommended.
    • For oral dosage form (suspension):
      • Adults and children weighing 48 kilograms (kg) or more—20 milliliters (mL) once a week for 2 doses (on Days 1 and 8).
      • Children weighing less than 48 kg—Dose is based on body weight and must be determined by your doctor.
        • Children weighing 10 kg to less than 48 kg—4 milligrams per kilogram (mg/kg) of body weight once a week for 2 doses (on Days 1 and 8).
        • Children weighing less than 10 kg—6 mg/kg of body weight once a week for 2 doses (on Days 1 and 8).

Missed dose

If you miss a dose of brincidofovir, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.


Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Throw away any unused oral liquid.

Precautions while using brincidofovir

It is very important that your doctor check your progress at regular visits to make sure brincidofovir is working properly. Blood tests may be needed to check for unwanted effects.

Using brincidofovir while you are pregnant can harm your unborn baby. If you are a woman who can bear children, your doctor may give you a pregnancy test before you start using brincidofovir to make sure you are not pregnant. Brincidofovir may also cause birth defects if the father is using it when his sexual partner becomes pregnant. Female patients should use an effective form of birth control during treatment with brincidofovir and for at least 2 months after the last dose. Male patients who have female partners should use effective birth control during treatment with brincidofovir and for at least 4 months after the last dose. If you think you have become pregnant or your partner has become pregnant while using brincidofovir, tell your doctor right away.

Do not use brincidofovir if you are also receiving cidofovir injection.

Brincidofovir may cause serious liver problems. Check with your doctor right away if you have dark urine, general tiredness or weakness, light-colored stools, nausea and vomiting, upper right stomach pain, or yellow eyes and skin.

Check with your doctor right away if you have diarrhea, nausea, vomiting, or stomach pain. These could be symptoms of a serious stomach or bowel problem.

Some men who use brincidofovir have become infertile (unable to have children).Talk with your doctor before using brincidofovir if you plan to have children.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Brincidofovir side effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

  • Diarrhea
  • nausea

Less common

  • Stomach pain or cramps
  • swelling of hands, ankles, feet, or lower legs
  • vomiting

Incidence not known

  • Dark urine
  • decreased appetite
  • light-colored stools
  • unusual tiredness or weakness
  • yellow eyes and skin

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common

  • Acid or sour stomach
  • belching
  • change in taste
  • heartburn
  • indigestion
  • itching skin
  • loss of taste
  • muscle weakness
  • rash with flat lesions or small raised lesions on the skin
  • stomach discomfort or upset

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

More about brincidofovir

Patient resources

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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.